Help with an Alembic inspired Fernandes MH-110 wiring

[Rjsharpe]

Hi guys,

I run a local guitar tech business and a new client has brought me quite a rare find. A 1989 Fernandes MH-110 with active pickups, a middle dummy coil and a M1D1 circuit! For playability, the guitar is setting up really well, but I am having an issue with the electronics and unfortunately am having a lot of trouble tracing down the issue.

Has anyone seen this model before or may know where I could find a schematic on a model like this? Here are a few photos if that is helpful for my fact finding.

Thanks very much in advance!

https://www.thegearpage.net/board/index.php?threads/help-with-a-1980-fernandes-mh-110.2431699/#post-36266055

[fivestringdan]

There is no MIDI control on that guitar. It is a 5 pin output for power and signal.

[lbpesq]

Hi Rob.

I have three of the MH-110 Masterhand guitars I’ve collected over the past 15-20 years. On one, I completely replaced the electronics with Alembic electronics, though not Series. I converted the humcanceller to a middle pickup and added RMC piezo saddles and a 13-pin jack to run a Roland GR-33. My other two have issues. My intention, one of these days when I have the time, is to try and combine the two into one guitar with original electronics. While the build quality on these is quite excellent, the original electronics paled in comparison to the real thing. These are a few club members here who have Fernandes Alembic copy basses (MH-110B; FAB-180) who can probably attest to the difference in electronics.

Here’s link to an old thread about mine: https://club.alembic.com/index.php?topic=20043.msg205426#msg205426

Good luck with yours and please keep us posted on your progress.

Bill, tgo

[Rjsharpe]

There is no MIDI control on that guitar. It is a 5 pin output for power and signal.

Thanks for the clarification. Do you have any information on what the positions of the rotary switch correspond to?

[gtrguy]

I have a similar Fernandes FAG (Fernandes Alembic Guitar) which I have been messing around with off and on over the years. What issues are you having? The 'Ferbic' circuit board is somewhat similar to the Alembic Series one, but with many components of less quality. The trimmers are not very good and I would put an ohm meter across them to see if they are passing juice. I'll attach a couple pics.


I believe the Ferbic power supply is designed to put out 9 volts and not the higher voltage the Alembic power supply puts out. You can get away with using an Alembic power supply but it does push the components harder than they are designed for. I also think the 2 internal 9 volt batteries in the Ferbic are designed to also put out 9 volts and not 18.


The pictured schematic is from a Kawai and not a Fernandes but might be of use.

[gtrguy]

The values on my picture of my Ferbic board are actual and not necessarily the designed ratings. The ICs are a common ones and easy to find. Alembic uses more of them than Fernandes. I replaced mine by installing sockets in the board.

[gtrguy]

The rotary switch probably is both PUPs off, Neck on, Both on , and Bridge on or some variation of that.

[Rjsharpe]

The rotary switch probably is both PUPs off, Neck on, Both on , and Bridge on or some variation of that.

Thanks very much for the response!  The issue I’m experiencing is that the two dials on the rotary switch that I would presume to be the bridge pickup are completely silent. I’ve put a meter on the hot and ground of the pickup and it is still alive. Interestingly, when in the neck pickup position, it seems as if both pickups are on and even the dummy coil has a signal. The bridge volume and tone pots have no function. Your values for the pickups are relatively in accordance with what I’m seeing.

[StephenR]

Thanks very much for the response!  The issue I’m experiencing is that the two dials on the rotary switch that I would presume to be the bridge pickup are completely silent. I’ve put a meter on the hot and ground of the pickup and it is still alive. Interestingly, when in the neck pickup position, it seems as if both pickups are on and even the dummy coil has a signal. The bridge volume and tone pots have no function. Your values for the pickups are relatively in accordance with what I’m seeing.

I am not familiar with the Fernandes circuit but since it emulates a Series circuit it may behave in similar fashion. If you are testing using only batteries it would be normal for an older Alembic instrument where the 1/4" jack is wired in stereo to only provide output from the neck pickup when using the 1/4" jack. On the Alembic Series basses where the 1/4" jack is wired in stereo you either need to use the five-pin cable and a power supply or a cable that connects to the 1/4" jack that has resistors added to sum the output to mono. A lot of owners of old Series basses have the 1/4" jack rewired for mono output so they don't need to use the power supply or a special cable summed to mono. The problem with using only batteries with a Series bass circuit is the amount of battery drain. Batteries will only last a bit over 20 hours. Using the power supply is the way to go. Does the owner of the Fernandes have the power supply and five-pin cable? It is sounding like there is nothing at all wrong with the instrument itself unless there are additional issues.

[Rjsharpe]

Thanks very much for the response!  The issue I’m experiencing is that the two dials on the rotary switch that I would presume to be the bridge pickup are completely silent. I’ve put a meter on the hot and ground of the pickup and it is still alive. Interestingly, when in the neck pickup position, it seems as if both pickups are on and even the dummy coil has a signal. The bridge volume and tone pots have no function. Your values for the pickups are relatively in accordance with what I’m seeing.

I am not familiar with the Fernandes circuit but since it emulates a Series circuit it may behave in similar fashion. If you are testing using only batteries it would be normal for an older Alembic instrument where the 1/4" jack is wired in stereo to only provide output from the neck pickup when using the 1/4" jack. On the Alembic Series basses where the 1/4" jack is wired in stereo you either need to use the five-pin cable and a power supply or a cable that connects to the 1/4" jack that has resistors added to sum the output to mono. A lot of owners of old Series basses have the 1/4" jack rewired for mono output so they don't need to use the power supply or a special cable summed to mono. The problem with using only batteries with a Series bass circuit is the amount of battery drain. Batteries will only last a bit over 20 hours. Using the power supply is the way to go. Does the owner of the Fernandes have the power supply and five-pin cable? It is sounding like there is nothing at all wrong with the instrument itself unless there are additional issues.


Thanks again for the additional response. No he got the guitar at a pawn shop many years ago and I don’t think he has any of the original cables. This in mind, does this mean I may be able to restore functionality simply by using a TRS cable rather than a standard TS guitar cable?

[Rjsharpe]

Thanks very much for the response!  The issue I’m experiencing is that the two dials on the rotary switch that I would presume to be the bridge pickup are completely silent. I’ve put a meter on the hot and ground of the pickup and it is still alive. Interestingly, when in the neck pickup position, it seems as if both pickups are on and even the dummy coil has a signal. The bridge volume and tone pots have no function. Your values for the pickups are relatively in accordance with what I’m seeing.

I am not familiar with the Fernandes circuit but since it emulates a Series circuit it may behave in similar fashion. If you are testing using only batteries it would be normal for an older Alembic instrument where the 1/4" jack is wired in stereo to only provide output from the neck pickup when using the 1/4" jack. On the Alembic Series basses where the 1/4" jack is wired in stereo you either need to use the five-pin cable and a power supply or a cable that connects to the 1/4" jack that has resistors added to sum the output to mono. A lot of owners of old Series basses have the 1/4" jack rewired for mono output so they don't need to use the power supply or a special cable summed to mono. The problem with using only batteries with a Series bass circuit is the amount of battery drain. Batteries will only last a bit over 20 hours. Using the power supply is the way to go. Does the owner of the Fernandes have the power supply and five-pin cable? It is sounding like there is nothing at all wrong with the instrument itself unless there are additional issues.

Thanks again for the additional response. No he got the guitar at a pawn shop many years ago and I don’t think he has any of the original cables. This in mind, does this mean I may be able to restore functionality simply by using a TRS cable rather than a standard TS guitar cable?

[lbpesq]

Yes, a TRS plugged into the guitar that “Y”s to two standard 1/4”plugs may work.  If it does you should expect to see one pickup out of one 1/4” plug, and the other pickup out of the other plug.   The 5-pin jack brought both pickup signals to the power supply which also could either send each pickup to a separate signal or sum the two to one signal.

Bill, tgo

[Rjsharpe]

Yes, a TRS plugged into the guitar that “Y”s to two standard 1/4”plugs may work.  If it does you should expect to see one pickup out of one 1/4” plug, and the other pickup out of the other plug.   The 5-pin jack brought both pickup signals to the power supply which also could either send each pickup to a separate signal or sum the two to one signal.

Bill, tgo

Thanks very much Bill. This certainly puts me further along than where I was. Much appreciate all of the advice.

[gtrguy]

I think you may be able to plug in a headphone into the 1/4 jack and see if you get both pickups.

[Rjsharpe]

I think you may be able to plug in a headphone into the 1/4 jack and see if you get both pickups.

Ahh very good idea bill.  I’ll give this a try.